The present invention relates to a vacuum pump used as gas exhaust units and the like of process chambers and other sealed chambers in a semiconductor manufacturing apparatus, a flat panel display manufacturing apparatus, and a solar panel manufacturing apparatus.
As the vacuum pump of this type, for example, a vacuum pump described in Japanese Patent Application Laid-Open No. 2002-21775 has been publicly known. In the vacuum pump descried in Japanese Patent Application Laid-Open No. 2002-21775 (hereinafter referred to as “conventional vacuum pump”), as a means for preventing adhesion of a product in the pump, an alternating current is fed to a coil (25) illustrated in FIG. 2 of Japanese Patent Application Laid-Open No. 2002-21775 to raise the temperatures of a good heat conductor (24) and a heat radiation plate (20) and heat gas channels of a moving blade (5), a stationary blade (4), and a thread groove pump stage (9) through the heat radiation plate (20).
However, in the conventional vacuum pump, although the gas channels of the moving blade (5), the stationary blade (4), and the thread groove pump stage (9) can be heated as explained above, a lower side in a casing (1) cannot be heated (see FIG. 2 of Japanese Patent Application Laid-Open No. 2002-21775). Therefore, there is a problem in that the product easily adheres to the lower side in the casing (1) and an adhesion amount of the product in the vacuum pump as a whole is relatively large.
With the conventional vacuum pump, as illustrated in FIG. 2 of Japanese Patent Application Laid-Open No. 2002-21775, the coil (25) is housed in the good heat conductor (24) and a wire of the coil (25) is connected to a connector (26) piercing through the good heat conductor (24). Therefore, it is also likely that a trouble of a vacuum pump electric system due to magnetic flux leak occurs, for example, magnetic flux leaks from a through-hole (a hole through which the wire of the coil (25) is inserted) of the good heat conductor (24) and the wire of the coil (25) and electric components inside the vacuum pump malfunction because of the leaked magnetic flux.
Incidentally, in the conventional vacuum pump, gas in a gas inlet port (2) flows in the direction of an outlet port (3) through the gas channels of the moving blade (5), the stationary blade (4), and the thread groove pump stage (9), whereby the inlet port (2) side changes to a high vacuum and, on the other hand, the outlet port (3) side changes to a low vacuum (see the description of paragraph 0052 of Japanese Patent Application Laid-Open No. 2002-21775). When the outlet port (3) side changes to the low vacuum, a downstream side of the thread groove pump stage (9) close to the outlet port (3) also changes to the low vacuum.
However, with the conventional vacuum pump, as explained above, since the coil (25) is disposed downstream of the thread groove pump stage (9) that changes to the low vacuum (see FIG. 2 of Japanese Patent Application Laid-Open No. 2002-21775), insulating coating breakage of the coil (25) due to vacuum electric discharge occurs and the life of the coil (25) is short. There is also a problem in that a failure of the pump electric system such as a short circuit due to the insulating coating breakage of the coil (25) occurs and the vacuum pump cannot be stably continuously operated for a long period.
In the conventional vacuum pump, the connector (26) is attached to the lower outer circumference of the casing (1), the connector (26) and the coil (25) are connected by a wire (no reference numeral), and an alternating current is fed from the connector (26) to the coil (25) via the wire (see FIG. 2 of Japanese Patent Application Laid-Open No. 2002-21775).
However, with the conventional vacuum pump, an end side of the connector (26), in particular, a side to which the wire is connected is disposed in a vacuum in the casing (1) (see FIG. 2 of Japanese Patent Application Laid-Open No. 2002-21775). Therefore, an expensive vacuum connector has to be used as the connector (25) (see the description of paragraph 0051 of Japanese Patent Application Laid-Open No. 2002-21775). There is also a problem in that costs of the vacuum pump as a whole are inevitably high.
The discussion above is merely provided for general background information and is not intended to be used as an aid in determining the scope of the claimed subject matter. The claimed subject matter is not limited to implementations that solve any or all disadvantages noted in the background.